1. Field of the Invention
The present invention relates to a display device having display circuits arranged in a matrix configuration.
2. Description of the Related Art
Conventionally, liquid crystal display devices are known as low power consumption display devices that can assume a thinner and more lightweight form and are employed in various types of equipment as display devices. Liquid crystal display devices (hereinafter referred to as LCD) have two substrates with electrodes formed on opposing sides thereof, laminated with liquid crystals injected between them. A display operation is performed by applying a voltage signal across the electrodes to control the alignment of the liquid crystals, the optical characteristics of which change according to the alignment so as to control the transmissivity of light from a light source.
It is well known that when a DC voltage is continuously applied across electrodes formed on opposing surfaces of the substrates, the alignment of the liquid crystal molecules becomes fixed, namely, the problem of screen burn-in occurs. Thus, an AC voltage signal having a polarity that periodically inverts with respect to a reference voltage is conventionally used as the voltage signal for driving the liquid crystals.
Well known methods for inverting the polarity of the liquid crystal driving voltage signal in a liquid crystal display device having a plurality of pixels arranged in a matrix configuration are inversion at every frame, inversion at every vertical scan (1V) or field, inversion at every horizontal scan (1H), and inversion at every pixel (dot). A frame unit corresponds to a frame in an NTSC signal, for example, and a field unit corresponds to various units (for example, odd fields and even fields) of a plurality of fields forming one frame.
In Japanese Patent Laid-Open Publication No. 2003-150127, the dot inversion method for inverting the polarity in one-pixel (dot) units is preferable among the above-mentioned methods as the adverse effect of inversion on display quality is least likely to appear. However, a problem was that its driving method is likely to become complex.
It should be noted that modifying the voltage of an SC line, which is a line that becomes a base for a storage capacitance, has been proposed in the dot inversion method in Japanese Patent Laid-Open Publication No. 2003-150127.